Pemasutta 9.2

9.2

Idha, bhikkhave, bhikkhu rūpaṃ attato samanupassati, rūpavantaṃ vā attānaṃ, attani vā rūpaṃ, rūpasmiṃ vā attānaṃ;

It’s when a mendicant regards form as self, self as having form, form in self, or self in form.